WBI-5111: A Small Molecule CAIX Inhibitor

The first-in-class small molecule anti-cancer drug candidate, WBI-5111, selectively inhibits the enzyme Carbonic Anhydrase IX (CAIX) which is expressed on the cell surface of hypoxic (oxygen depleted) tumour cells (particularly cancer stem cells), and is one of the major functional regulators of cancer cell survival and metastasis. CAIX is well established as a specific target for solid cancers and has been validated in many animal tumor models.

CAIX is expressed at highly restricted levels in only a few normal tissues and cells. Elevated expression of CAIX has been reported in numerous types of human solid cancer cells including breast, renal, lung, colon, thyroid, bladder, oesophageal, oligodendroglial and cervical cancers. Importantly, CAIX expression is highly correlated with mortality and morbidity in cancer patient populations. The role of CAIX in tumorigenesis and cancer metastasis has been widely demonstrated in vitro and in vivo.

WBI-5111 is designed to selectively target CAIX enzymatic activity in cancer cells. Its anti- cancer activities including anti-tumor growth and anti-metastasis have been demonstrated in several animal models both as a monotherapy and/or as a combination with other chemotherapeutic agents. Currently, WBI-5111 is under evaluation in a multi-centered phase I clinical study to establish a maximum tolerable dose and pharmacokinetics in cancer patients. The completion of the study is anticipated by Q1 2016.